Floating bridge

ABSTRACT

A floating bridge system with hinged, pivotable floats for folding and stacking them for overland transport and for spreading and unfolding them for floating. Pivoting of the floats is carried out through pumps disposed in the principle float, and operating in a closed system for pressurizing hydraulic actuators. The pumps are releasably connectable to amphibious tractors by means of shaft couplings.

United States Patent Haensgen [is] 3,656,198 [4511 Apr. 18, 1972 [54] FLOATING BRIDGE [72] Inventor: Klaus Haensgen, Witten, Germany [73] Assignee: Lohmann 8: Stolterfoht Aktiengesellschaft,

Witten, Germany [22] Filed: Sept. 4, 1970 [21] Appl. No.: 69,622

[30] Foreign Application Priority Data Sept. 17, 1969 Germany ..P 19 48 071.8

[52] US. Cl ..l4/27 [51] Int. Cl ...E01d 15/08 [58] Field olSearch ..I4/1,27

[56] References Cited UNITED STATES PATENTS 3,010,128 11/1961 Gillois ..14/1

3,152,569 10/1964 Gehlen 14/27 X FOREIGN PATENTS OR APPLICATIONS 1,061,067 3/1967 Great Britain ..I4/l

Primary Examiner-Jacob L. Nackenofi Attorney-Smyth, Roston & Pavitt [57] ABSTRACT A floating bridge system with hinged, pivotable floats for folding and stacking them for overland transport and for spreading and unfolding them for floating. Pivoting of the floats is carried out through pumps disposed in the principle float, and operating in a closed system for pressurizing hydraulic actuators. The pumps are releasably connectable to amphibious tractors by means of shaft couplings.

7 Claims, 2 Drawing Figures FLOATING BRIDGE The present invention relates to improvements in selfpropelled, crossing and floating bridge structure system which is comprised of a floating bridge proper and of one or two amphibious tractors. The floating bridge proper is comprised of a plurality of hingedly interconnected floats that include, for example, a principal float and one or more, for example, two auxiliary floats. A first auxiliary float is hinged to the principal float for pivoting on a first axis; that first auxiliary float is hinged to a second auxiliary float for pivoting the latter on a second, parallel axis, etc. Hydraulical actuators are provided to obtain pivoting of the floats. The floats are folded up into a vertically stacked disposition for overland transportation, or they are unfolded to extend coplanar as to one each of their respective largest surfaces, so as to establish a large interconnected floating structure which is composed of these individual floats, now being placed side by side. After having been folded together, two oppositely directed, short sides of the principal float are coupled to the two tractors. The two tractors do in fact carry the folded floats for overland transportation. Structure of this type is disclosed, for example, in copending application of common assignee, 848,319, filed Aug. 7, 1969 now U.S. Pat. No. 3,613,139.

It is an object of the invention to provide particular actuating and operating means for the hydraulically operated pivot mechanism that provides for the folding and unfolding of the floats, and to provide particularly operated pumping equipment for permitting the amphibious tractors to be coupled or decoupled from the expanded unfolded float when floating, without water or other impurities seeping into the hydraulic system.

Other known floating structures do not experience that problem, particularly in those cases where the driving means, such as a tractor, and the floating bridge are permanently interconnected and constitute a permanently connected unit. German Pat. No. 1,019,339 and the corresponding U.S. Pat. No. 3,010,128, for example, show a vehicular bridge comprised of a principal vehicle with pivotable ramps. The ramps are pivoted, i.e. folded up for overland transportation. An amphibious crossing vehicle is disclosed in Soldat und Technik," Vol. 2, 1967, page 312. The vehicle described therein is basically a pontoon-like body with a caterpillar type frame for overland drive. The pontoon body is provided with a laterally pivotable, second or auxiliary boat that can be folded down and is somewhat longer than the principal boat. These latter structures are mentioned here only for purposes of general orientation; principal object of the invention is to improve structure as outlined in the introduction. The improvement refers particularly to hydraulic actuation of pivoting the floats on their respective hinge axis.

In accordance with the principal concept of the invention it is suggested that for operating hydraulic actuators for folding and unfolding the floats, there are provided pumping means for pressurizing suitable liquid to obtain folding and unfolding of the floats as needed. The pumping means are disposed in the interior of the principal float, and the drive shaft, or shafts, of the pumping means traverse one or both smallest sides of the principal float to which the tractors are coupled on demand. Releasable shaft coupling(s) connect the pumping means drive shaft(s), as projecting from the principle floats, to driven shaft(s) as projecting from the adjacent tractor. Thus, the point of separation between prime mover and hydraulic system is relocated; in particular, floating structure and amphibious tractors, when separated, have pump and pump drive disconnected. This way, the hydraulic system remains a close system as to fluid conduction and circulation and is not subject to that separation. Therefore, water or any other impurities will not seep into the hydraulic system, the hydraulic system remains leak-proof to the extent its construction is leak-proof.

It should be mentioned that hydraulic pumping as providing folding and unfolding of the float, is not needed when the unfolded floats are in use as floating platform or the like. Also, the tractors are usually not needed permanently at the platform, at least not all of them; some may be needed for maneuvering. Prior to restoration of the on-land folded-up condition, the tractors will always be reconnected, and pumping and folding operation is needed only then. Automatically releasable shaft clutches can be used for connecting pumping means and drive. These clutches are rather :sturdy and can withstand rough treatment under difficult environmental conditions. In particular, these clutches permit automatic connection or disconnection as between tractor and float.

Basically, two possibilities are available for practicing the invention, particularly when one principal float and two auxiliary floats are involved. One form of practicing the invention is characterized by two reversible pumps in the principal float, one for pressurizing the hydraulically operated actuator for pivoting the first auxiliary float on the hinge axis with the principal float; the other pump operates the hydraulical actuator for pivoting the second auxiliary float on the hinge axis with the first auxiliary float. Each pump, thus, operates the respective actuator in either direction for folding and for unfolding.

In accordance with the second embodiment there is a first, unidirectionally operating pressure pump provided for folding the auxiliary floats as about both axes. A second unidirectional, but oppositely effective pump provides for unfolding.

Either pump system may be duplicated in the principal float, to permit operation from either tractor. Additionally or alternatively, half of the total number of pumps may be coupled to and operated by one tractor, the other half by the other tractor.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the objects and features of the invention and further objects, features and advantages thereof will be better understood from the following description taken in connection with the accompanying drawings in which:

FIG. 1 illustrates somewhat schematically a side view of the folded bridge structure with tractors coupled thereto for overland transportation and improved in accordance with the preferred embodiment of the present invention; and

FIG. 2 illustrates somewhat schematically a hydraulic system in accordance with the preferred embodiment of the present invention showing the floating bridge unfolded.

The self-propelled crossing and floating bridge structure is comprised of a bridge proper which includes three floats hinged together. The three floats are comprised of a principal float 1 and two auxiliary floats 2 and 31 illustrated in the folded or collapsed condition for overland transportation in FIG. 1. The respective largest surfaces of each float extend transverse to the plane of the drawing of FIG. 1 and appear vertically stacked. FIG. 2 shows the floats unfolded for floating, whereby the mutually facing, large surfaces of floats 1 and 2, and the upper large surface of float 3, as shown in FIG. 1, will be disposed coplanar, side-by-side to establish a relatively large platform surface. The floats are delineated schematically only in FIG. 2, as emphasis is placed on the internally disposed hydraulic equipment.

The principal float l is carried by two amphibious tractors 4 and 5 in FIG. 1. The two tractors 4 and 5 are respectively pivotally linked to float 1 by means of releasable coupling structure extending from oppositely oriented, smallest sides 10 and lb of principal float 1. The wheels of the tractors are retractable.

Hinges l6 pivotally link principal float 1 to auxiliary float 2, while hinges l7 link the latter auxiliary float to float 3. The hinge axes as defined by hinges l6 and 17 are parallel to each other, and these axes extend in direction along which sides la and 1b face, but, of course, opposite to each other. The folding and unfolding is shown per se in the said copending application, including the hinge mechanism, see FIGS. 12 and 13 thereof.

Two pressure liquid pumps 6 and 7 are provided in the principal float 1. The two pumps respectively have drive shafts 8 and 9 which traverse the two oppositely directed front ends, 1a and lb, of the principal float, and they are respectively releasably coupled to tractors 4 and 5. In particular, a shaft 12 projects from tractor 4 and is connected to pump shaft 8 by means of a releasable shaft clutch coupling 10. A similar clutch or coupling 11 connects a shaft 13 of tractor to pump shaft 9. l4 and respectively refer to reversible drive means for the shafts l2 and 13. These devices 14 and 15 may include a gear box that couples the shafts to the respective engines of the tractors. Alternatively, 14 and 15 denote auxiliary engines or motors.

As can be seen best from FIG. 2, showing the three floats in an unfolded position to serve as floating bridge, a hydraulic actuator 18 is coupled to floats 1 and 2 to pivot them on the axis as defined by the two hinges 16 between floats l and 2. The hydraulic actuator 18 has opposite sides coupled to opposite outlets of pump 6 via pipes and/or hoses 22 Thus, depending upon the direction of rotation, as imparted by shaft 12 of tractor 4 upon pump 6, float 2 is folded up or down. Pump 7, in turn, is driven from tractor 5 to operate a hydraulic actuator 19 pivoting float 3 relative to float 2 on the axis as defined by hinges l7. Pipes 20 couple opposite sides of pump 7 to opposite sides of hydraulic actuator 19.

It can readily be seen in FIG. 2 that the hydraulic lines, denoted in dash-dot lines, are contained within floats l, 2 and 3, as a closed hydraulic system. The particular bridge structure as shown in FIG. 1 and 2, actually shows the invention twice, so that the folding and unfolding can be carried out from either tractor. Thus, tractor 5 is presumed to have a second auxiliary engine or gear box 15a, also being reversible as to rotation of its output shaft 13a. Another pump, pump 7a, is disposed adjacent the pump 7 and is releasably coupled to shaft 13a via clutch 11a. Pressure lines link this pump with hydraulically operated actuator 18 for hingedly pivoting float 2 relative to float 1. Thus, float 2 can be pivoted by operation of either pump 70 or 6, or the pumps can operate concurrently and in parallel so that folding or unfolding is carried out at twice the speed.

Analogously, a fourth pump 6a is connected in parallel to pressure pump 7, for operating actuator 19 from either tractor. Upon concurring operation of the two pumps 60 and 7 folding and unfolding of float 3 relative to float 2 is carried out at twice the speed. It can readily be seen that, looking in the direction of forward driving of either tractor, the respective shaft extending from the rear left of a tractor provides hinge operation on floats 2 and 3, and the shaft extending from the rear right of the same tractor provides hinge operation on floats l and 2 so that actually either tractor can be hooked up to either side of float 1.

The alternative version of the invention can readily be deduced from FIG. 2. Assuming, each of the pumps 6, 6a, 7, 7a, is unidirectional, operation of pumps 7 and 7a may lead to folding; operation of pumps 6 and 6a may lead to unfolding. Each pair of such pumps, 7 and 7a, 6 and 6a, may readily be replaced by a single pump operating both actuators.

The partially illustrated pipes 21 lead to further, not illustrated hydraulically operated actuators, operating in parallel to actuators l8 and 19, so as to obtain a more balanced application of forces.

The invention is not limited to the embodiments described above but all changes and modifications thereof not constituting departures from the spirit and scope of the invention are intended to be included.

I claim:

1. In a crossing and floating bridge type system including a plurality of hingedly connected floats for folding the floats into a first, vertical stacking disposition of their largest surfaces for overland transport, and unfolding them into a second disposition, wherein the largest surfaces are disposed horizontally side by side to establish a composite float, having at least one platform surface established by one largest side each per float, the hinge axes being parallel to each other and to a first horizontal direction, there being hydraulicall operable means for folding and unfolding the oats by pivo ing them on the respective hinge axes, the system further including a pair of amphibious tractors releasably coupled to opposite ends of one of the floats, as taken along said direction, the improvement comprising:

hydraulic pumping means disposed in the one float and coupled to the hydraulically operable means for control of the folding and unfolding in dependence upon operation of the pumping means, the pumping means connected to the hydraulically operable means independently from connection of either tractor of the pair to the one float to establish a closed hydraulic system;

at least one drive shaft coupled to the pumping means and traversing the one end of the one float;

means in at least one of the tractor for providing rotary motion and imparting same upon a shaft projecting from the tractor; and releasable shaft coupling means for connecting the tractor shaft to said drive shaft.

2. In a system as in claim 1, the pump means comprised of at least two pumps disposed adjacent opposite ends of said one float and having drive shafts respectively for connection to the two tractors.

3. In a system as in claim 1, the pump means comprised of four pumps, disposed in pairs adjacent opposite ends of said one float, each pump having a drive shaft, each tractor having a pair of rotary outputs, there being four shaft couplings for coupling to the shafts as projecting from the one float, respectively to the two outputs each of the two tractors.

4. In a system as in claim 1, the pump means including a pair of reversible pumps, there being a first actuator included in the hydraulically operable means, being coupled to one pump of the pair to pivot a second float on a hinge axis relative to the one float, there being a second actuator included in the operable means, being coupled to the other pump of the pair to pivot a third float on a hinge axis relative to the second float.

5. In a system as in claim 4, the pumps of the pair disposed adjacent opposite ends of the one float, to be coupled individually to the two tractors.

6. In a system as in claim 4, the pumps of the pair disposed on the same end of the one float, to be coupled individually to the same tractor on that side.

7. In a system as in claim 5, the pump means including pumps operating for folding the floats, and additional pumps operating for unfolding the floats. 

1. In a crossing and floating bridge type system including a plurality of hingedly connected floats for folding the floats into a first, vertical stacking disposition of their largest surfaces for overland transport, and unfolding them into a second disposition, wherein the largest surfaces are disposed horizontally side by side to establish a composite float, having at least one platform surface established by one largest side each per float, the hinge axes being parallel to each other and to a first horizontal direction, there being hydraulically operable means for folding and unfolding the floats by pivoting them on the respective hinge axes, the system further including a pair of amphibious tractors releasably coupled to opposite ends of one of the floats, as taken along said direction, the improvement comprising: hydraulic pumping means disposed in the one float and coupled to the hydraulically operable means for control of the folding and unfolding in dependence upon operation of the pumping means, the pumping means connected to the hydraulically operable means independently from connection of either tractor of the pair to the one float to establish a closed hydraulic system; at least one drive shaft coupled to the pumping means and traversing the one end of the one float; means in at least one of the tractor for providing rotary motion and imparting same upon a shaft projecting from the tractor; and releasable shaft coupling means for connecting the tractor shaft to said drive shaft.
 2. In a system as in claim 1, the pump means comprised of at least two pumps disposed adjacent opposite ends of said one float and having drive shafts respectively for connection to the two tractors.
 3. In a system as in claim 1, the pump means comprised of four pumps, disposed in pairs adjacent opposite ends of said one float, each pump having a drive shaft, each tractor having a pair of rotary outputs, there being four shaft couplings for coupling to the shafts as projecting from the one float, respectively to the two outputs each of the two tractors.
 4. In a system as in claim 1, the pump means including a pair of reversible pumps, there being a first actuator included in the hydraulically operable means, being coupled to one pump of the pair to pivot a second float on a hinge axis relative to the one float, there being a second actuator included in the operable means, being coupled to the other pump of the pair to pivot a third float on a hinge axis relative to the second float.
 5. In a system as in claim 4, the pumps of the pair disposed adjacent opposite ends of the one float, to be coupled individually to the two tractors.
 6. In a system as in claim 4, the pumps of the pair disposed on the same end oF the one float, to be coupled individually to the same tractor on that side.
 7. In a system as in claim 5, the pump means including pumps operating for folding the floats, and additional pumps operating for unfolding the floats. 